Sam’sClubOfferingiPhone4SPreordersNowForFridayPickup

Sam’s Club members looking to score an iPhone 4S on Friday are in luck. Select stores are now taking preorders for Friday pickup, according to news first published by MacRumors.
To qualify, you must first be a Sam’s Club member (obviously) and live near a store offering the preorders. Luckily, according to Sam’s Club official iPhone 4S page, it looks like most of its stores are a part of this promotion.
According to this page, preorders are being taken now (they started at 10 a.m. today) and naturally, are on a first-come, first-served basis.
Sam’s Club recommends the following:

Before You Arrive
Sign up for a Sam's Club Membership if you don't already have one by visting the Member Service page.
Upgrade your existing iPhone to the latest iOS release. Just connect your iPhone to your Mac or PC and follow the onscreen instructions in iTunes.
Back up the data on your existing iPhone to iCloud or your computer. For instructions on how to back up your iPhone, read this Support page.
Create a new Apple ID if you don't already have one by visiting the Apple ID page.
What To Bring With You
Your old mobile phone, if you're replacing it.
Social Security number of the primary account holder.
Valid government-issued photo ID.
Carrier account password, if you have one.
Your Sam's Club Membership.
Your Apple ID and password.

If you haven't already preordered your iPhone 4S, here is yet another way of doing so. Good luck!